function k =Beam1D2Node_Stiffness(E,I,L)
k = E*I/(L*L*L)*[12 6*L -12 6*L
				6*L 4*L*L -6*L 2*L*L
   				-12 -6*L 12 -6*L
   				6*L 2*L*L -6*L 4*L*L];
